Core Center Program Objectives: The Pittsburgh Transfusion Medicine/Hemostasis Research Network (PTN) seeks to contribute to important multicenter clinical trials in transfusion medicine and hemostasis by capitalizing on our three strengths: 1) The integrated delivery of transfusion medicine and coagulation services to all the major University of Pittsburgh Medical Center Health System (UPMCHS) hospitals by the University of Pittsburgh faculty at the Institute For Transfusion Medicine (ITxM);2) The extraordinary patient base afforded by the UPMCHS hospitals including a Pittsburgh Cancer Institute (PCI), adult and pediatric level I trauma centers, a largest organ transplant program, a children's hospital, a women's hospital and outpatient facilities including the Hemophilia Center of Western PA and PCI; and3) The extensive experience and extertice of all three core center investigators in running and/or participating in multicenter clinical trials in transfusion medicine and hemostasis. Specific Aims: We propose two protocols to accomplish these objectives:1) Prospective Randomized Trial of Activase in the Prevention of Central Venous Access Device Infection in Hemophilia" (Project 1); and2) Multi-center, Randomized, Controlled Clinical Trial of Plasma Exchange Therapy vs Standard of Care in Children with Thrombocytopenia Associated Multi-Organ Failure (Project 2)The Core Center will provide the infrastructure and oversight necessary for the successful implementation and execution of these trials including: management of the budget for each protocol, timely establishment of program network office, coordinate resources for the operation of each protocol (e.g., research nurse, data clerk), assure timely implementation and operation of new protocols (e.g., accrural, timely data reporting, patient follow up) through biweekly research meetings with protocol investigators, establish a local DSMB for each protocol, assist protocol investigators with data analysis, interpretation, and publication, establish a Community Advisory Group to educate the community and to discuss and disseminate study results, and work with other network sites to select and revise study protocols.